devel/py-b2: Update to 4.3.0

Changes since 4.2.0:

• Fix shell autocompletion for Python >=3.12.8 and >=3.13.1.
• Add --exclude-if-uploaded-after to sync.
• Add -l as an alias for --long argument.
• Remove yapf in favor of ruff.
• Upgraded to pytest 8.
• Use SHA384 for Windows signing instead of expired SHA256withRSA.